1. Technical Field
The invention relates to nozzle cleaning methods, nozzle cleaning devices, liquid ejection apparatuses, printing apparatuses, and computer-readable media.
2. Description of the Related Art
Inkjet printers are known as an example of printing apparatuses that carry out printing by ejecting ink onto various media such as paper, cloth, and film. These inkjet printers perform color printing by ejecting color inks such as cyan (C), magenta (M), yellow (Y), and black (K) to form dots on the medium. Ink ejection is carried out using nozzles.
However, with these inkjet printers, a nozzle may become clogged due to sticking of ink or the like such that ink is not ejected properly. Dots cannot be formed adequately on the medium when ink is not ejected properly from the nozzle in this way and problems may occur such as being unable to print images clearly.
Accordingly, various methods have long been proposed for testing whether or not ink ejection is functioning properly. As one of these, a detection method has been proposed (see JP-A-2000-233520) in which ink ejected from a nozzle is optically detected. In this testing method, the condition of ink ejection from the nozzle is examined by using a photodiode to detect whether or not a beam irradiated from an LED is blocked by the ink ejected from the nozzle. If the result of the test is that an ejection defect is discovered in the nozzle, then a cleaning process is executed on that nozzle. This enables nozzle ejection defects to be solved.
By the way, there are several causes of ejection defects occurring in nozzles. For example, there are causes such as ink ejection being unable to be carried out due to clogging or the like, or the direction in which ink is ejected deviates due to foreign objects adhering to the nozzle opening. However, regardless of there being several causes of nozzle ejection defects such as these, conventionally the cleaning processes executed on a nozzle in which an ejection defect has been discovered are invariably the same. That is, for example, a process may be performed in which extraneous matter adhering to the nozzle opening is removed by wiping or ink may be forcibly discharged from the nozzle. If the ejection defect is still not solved by this, then a process such as suctioning ink from the nozzle is performed. For this reason, considerable time is spent on the cleaning processes and extra ink is ejected, which incurs an increased burden of cost for the user.